Sound shield



Nov. 7, 1961 T. BREWER ETAL 3,007,539

SOUND SHIELD Filed Oct. 4. 1957 2 Sheets-Sheet 1 zwaAws z. eW #42 4. #022 15 BY PIA/VI). 502/520,.12.

ATTORNEYS Nov. 7, 1961 T. BREWER ETAL 3,007,539

scum) SHIELD Filed Oct. 4, 1957 2 Sheets-Sheet 2 54 W i FIG. 6 B

AT ToR NEYS Unite This invention relates to an extensible shield, and more particularly to an extensible sound absorbing and reflecting shield.

The invention has among itsobjects the provision of a novel extensible shield.

Another object of the invention is the provision of an extensible shield provided with panels having marked sound absorbing and reflecting properties.

Yet another object of the invention is the provision of an extensible shield of the type indicated which is easy to position and to adjust.

A further object of the invention is the provision of a novel sound absorbing and reflecting panel for a sound shield.

The above and further objects and novel features of the invention will more fully appear from the following description when the same is read in connection with the accompanying drawings. It is to be expressly understood, however, that the drawings are forthe purpose of illustration only and are not intended as a definition of the limits of the invention.

In the drawings, wherein like reference characters refer to like parts throughout the several views,

FIG. 1 is a view in perspective of an illustrative sound shield made in accordancewith the invention, the shield being shown in substantially collapsed condition;

FIG. 2 is a view in perspective of the shield of FIG. 1 in substantially fully'extended position;

FIG. 3 is a fragmentary view in elevation of a portion of the shield of FIGS. 1 and 2, the view being taken generally from the line 3-3 of FIG. 2;

FIG. 4 is a fragmentary View in elevation of a. modified panel-securing clip for use with the shield of the invention, a pantograph arm to which the clip is shown attached being in section;

FIG. 5 is a view in horizontal section through the shield, the sectioning plane being located immediately above the base of the shield in FIG. 2;

FIG. 6 is a fragmentary view in plan of a sound absorbing and reflecting panel for the shield of the invention, the forward, cellular plastic layer being removed from the main extent of the panel, a portion of the panel being shown with such forward layer in place and with successive layers of the panel thereunder broken away; and

FIG. 7 is a view in section through the panel of FIG. 6, the section being taken generally along the line 7-7 of FIG. 6.

The illustrative embodiment of extensible screen shown in the drawings is adapted primarily for shielding and confining the sound from devices such as jet air engines.

As is well known, airplane engines of the jet type, especially when running at high speed on the ground, emit a large volume of piercing noise. A plurality of screens in accordance with the invention may be employed substantially to surround an aircraft having one or more jet "ice engines, thereby to absorb and reflect the emitted sound so as to decrease the noise level beyond the screens.

The screen shown is generally designated by the reference character 10. Such screen includes a plurality of similar sound absorbing and reflecting panels 11 which are supported on a 'base structure 12 through the medium of two similar laterally-spaced pantographs each generally designated 14. Each of the pantographs includes a plurality of similar first arms 15 which incline upwardly in a direction from the front to the rear of the shield, and a plurality of second arms 16 which incline upwardly in a direction from the rear to the front of the screen. The arms 15 and 16 of each pantograph 14 are pivotally connected at their ends by pivot pins 23 and at their centers by cross rods 37.

On the forward end of platform 12, at the right in FIGS. 1 and 2, there are mounted two laterally-spaced upstanding U-shaped brackets 17 to which the lower ends of the lowermost arms 15 of the pantographs 14 are pivotally secured. The lower ends of the lowermost arms 16 of the pantographs carry stu-b shafts 20 on the outer ends of which are mounted guide rolls 21. Rolls 21 are guided for forward and rearward movement by opposed, spaced, inwardly open channel members 22 secured to the top 19 of platform 12. It will be apparent that when rolls 21 occupy the position shown in FIG. 5, pantographs 14 are in the fully extended position shown in FIG. 2, and that when such rolls are retracted to lie adjacent the other ends of channels 22 the pantographs are collapsed, as shown in FIG. 1. When the screen is fully extended, the panels approach the vertical, and the lower edge of an upper panel lies generally at the same level as the upper edge of a lower panel.

The pantographs are connected to be extended and collapsed as a unit by mechanism including an actuating yoke 24 and a cylinder 31 as more clearly shown in FIG. 5. Yoke 24 includes the parts 25, 26, 27, and 29, to be described. The inner end of each stub shaft 20 extends through a short longitudinally extending member 26, members 26 being rigidly connected by a transversely extending tubular member 25. Angularly extending for wardly from members 26 are two 'braces 27 which are connected to a central member 29. Member 29 is pivotally connected at 28 to the forward end of a piston rod 30 of a hydraulic cylinder 31. Cylinder 31 is pivotally mounted above the upper surface 19 of platform 12.

Cylinder 31 is selectively operated in reverse directions by fluid under pressure supplied by a motor driven bydraulic pump unit generally shown at 32. When fluid under pressure is delivered to the rear end of cylinder 31 through conduit 34 and fluid is exhausted from the forward end of the cylinder through conduit 35, piston rod 30 moves outwardly toward the position shown in FIG. 5. Piston rod 30 may be moved in the opposite direction by the reversal of the direction of the delivery of fluid to cylinder 31. The direction of movement of piston rod 30 may be controlled by the valve (not shown) under the control of control lever 36 on unit 32. It will be apparent that not only may cylinder 31 be employed either to extend the pantographs 14 from the position of FIG. 2 or to retract the pantographs, from the position of FIG. 2 to that of FIG. 1, but that by suitable manipulation of control lever 36 the pantographs may be held in any desired intermediate position, whereby the screen is held at the desired degree of extension.

As more clearly shown in FIG. 3 the cross rods 37 ex tending between the centers of the arms of the opposite pantographs are rigidly connected to panels 11. In the embodiment shown, rods 37 are welded at 39 to the frame members 54 of panels 11. As shown in FIG. 3, the outer ends of cross rod 37 extend through holes 13 and 18 in arms 16 and 15, respectively, of the pantographs 14 in such manner that the rod may pivot freely with respect to such arms. In the embodiment of FIGS. 1, 2, and 3, the top three panels 11 are maintained from free rotation about the axis of rods 37 by clips, generally designated 49, which as shown are attached to the underside of the panels adjacent their lower edges and to arms of the pantographs. The lowermost panel 11 is attached to an arm 15 by a clip 43 adjacent the upper edge of the panel. As a consequence, the panels 11 have a constant angular relationship with respect to the arms 15 of the pantographs, and in all adjusted positions of the screens the panels 11 are parallel to each other.

In some instances it is desirable that each of the panels 11 shall be adjustable in angle about the axis of its re spective rod 37. In FIG. 4 there is shown an alternative clip, generally designated 46, which may be substituted for clips 40 and 43 to allow such angular adjustment of panels 11. Clip 46 has a split clamp portion 47 which engages arm 15 of a pantograph, portion 47 mounting a first vertically disposed plate member 49. Another plate member 50 carries an arm 51 having a swivel joint 53 therein. The free end of arm 51 is secured to the underside of panel 11 as by a rivet 52. Plate members 49 and 50 may be suitably adjusted relative to each other, whereby to change the angularity between the panel 11 and the arm 15, by removing studs 48 which secure plate members 49 and 50 together, moving the plate members relative to each other as required, and again securing them together by the studs 48.

If desired, the clips 40 (or the clips 46) may be omitted from the shield, panels 11 being connected to move with arms 15 of the pantographs by suitable spline connections between the outer ends of rods 37 and the passage 18 in arms 15. As a still further alternative, not here illustrated, the outer ends of rods 37 may, as in the embodiment shown, pivot freely with respect to the passage 18 and arms 15 of the pantographs, suitable means such as quadrants being non-rotatably aflixed to the outer ends of cross rods 37 The quadrants may be provided with a series of holes angularly spaced about the axis of rod 37, the holes receiving a removable pin which projects through a selected one of such holes into a hole in arm 15. Such construction allows the panels 11 to be suitably adjusted angularly about the axis of rod 37.

The construction of panels 11 will be more fully understood upon consideration of FIGS. 6 and 7 of the drawing. As there shown, panel 11 has an outer, forwardly open frame formed of metal angle members 54 which are welded together at the corners. The outer frame receives a panel body which in this instance is composed of a forward, thick layer 57 of elastic cellular material such as foamed polyurethane, a layer of reinforcing material in the form of expanded metal adhesively bonded to layer 57, a layer of imperforate metal 61 attached to the rear surface of layer 55, and a thinner rear layer 62 of elastic cellular material such as foamed polyurethane.

Reinforcing layer 55 is provided with strengthening strips of metal 56 which are secured thereto as by being welded thereto along the edges of layer 55. The combined layer 55 and edge strips 56 are secured to frame members 54 by means of wing nuts 64, which are conveniently welded to strips 56, and by bolts 65 disposed with their heads at the rear of panel 11.

After the layer 55 and strips 56 have been thus attached to frame members 54, layer 57, cut to appropriate size, is then bonded to the forward face of layer 55 as by the use of a suitable adhesive, indicated at 60,

applied to either one or both layers 55 and 57. The imperforate layer 61, which is preferably made of a heavy metal such as lead, may be attached to layer 55 in a suitable manner either before or after layer 57 has been applied thereto. Finally layer 62 is secured to the rear face of layer 61 as by the use of a suitable adhesive.

The forward faces of layer 57 of the panels 11 are preferably formed with a plurality of similar pyramidalshaped projections 59, which act to reflect sound between them, and thus to dissipate much of the sound energy. Imperforate layer 61 of metal, particularly when made of a heavy metal, is efficient in absorbing a large amount of the received sound energy and reflecting the remainder back into layer 59.

For use with mobile sources of sound, such as aircraft being serviced and tested at airports, it is preferred that the screen itself be mobile. For this purpose, platform 12 is provided with swivel mounted supporting wheels 44 which permit its being moved easily as by a tractor attached to a drawbar 45 secured to the platform.

Although only a limited number of embodiments of the invention have been illustrated in the accompanying drawings and described in the foregoing specification, it is to be expressly understood that various changes, such as in the relative dimensions of the parts, materials used, and the like, as well as the suggested manner of use of the apparatus of the invention, may be made therein without departing from the spirit and scope of the invention as will now be apparent to those skilled in the art.

What is claimed is:

1. An extensible sound shield comprising two laterally spaced similar pantographs, a horizontal base supporting the pantographs in a vertically extending position above said base, a plurality of similar aligned sound absorbing and reflecting panels spanning the distance between the pantographs, means to pivotally connect said panels substantially centrally thereof to the mid-points of the respective oppositely disposed arms of each pantograph, means to adjustably connect at least one edge of each panel to an adjacent similarly disposed arm of a pantograph whereby each panel in its adjustably connected position has a constant angular relationship with respect to the arms of the pantographs and with respect to adjacent panels in all adjusted positions of said pantographs, means to selectively extend and collapse the two pantographs as a unit, and means to hold the pantographs in adjusted postiion.

2. An extensible sound shield as defined in claim 1 wherein said means to adjustably connect at least one edge of each panel to the adjacent arm of a pantograph comprises a first plate secured to said pantograph arm and having a plurality of spaced apertures extending therethrough, a second plate having a transversely extending arm secured to said edge of said panel and having a plurality of spaced apertures extending through said plate, a swivl joint in said transversely disposed arm, said first and second plates being positioned in face to face relationship with at least one aperture in said first plate in register with an aperture in said second plate, and means passing through said aligned apertures whereby said plates are secured together.

References Cited in the file of this patent UNITED STATES PATENTS 264,751 Potts Sept. 19, 1882 1,193,013 Grant Aug. 1, 1916 2,076,994 Kanengeiser Apr. 13, 1937 2,116,270 Le Grand May 3, 1938 2,137,324 Wallach Nov. 22, 1938 2,140,210 Schenk Dec. 13, 1938 2,148,281 Scott Feb. 21, 1939 2,197,445 Youker Apr. 16, 1940 (Other references on following page) Piacentini Nov. 12, 1940 Beckwith et a1. July 20, 1943 Wolfi Aug. 22, 1944 Nostrand May 15, 1945 Herron June 26, 1945 Smith et a1 Ian. 29, 1946 Walter et a1. July 4, 1950 Tucker Aug. 15, 1950 10 Kropa et a1. Nov. 20, 1951 Phillips Mar. 25', 1952 Pridy Nov. 11, 1952 Vicci Oct. 6, 1953 Page Nov. 16, 1954 DEustachio Mar. 8, 1955 Maccaferri July 24, 1956 Holtsford Mar. 12, 1957 FOREIGN PATENTS France Apr. 8, 1953 Great Britain Jan. 5, 1955 

